Delete the WordPress User When a Paid Memberships Pro Member Cancels His Account

gistfile1.php

/*
	Requires PMPro v1.4+
	Code to delete WP user accounts when a member cancels their PMPro account.
	Users are not deleted if:
	(1) They are not cancelling their membership (i.e. $level_id != 0)
	(2) They are an admin.
	(3) The level change was initiated from the WP Admin Dashboard 
	(e.g. when an admin changes a user's level via the edit user's page)
*/
function my_pmpro_after_change_membership_level($level_id, $user_id)
{
	//are they cancelling? and don't do this from admin (e.g. when admin's are changing levels)
	if(empty($level_id) && !is_admin())
	{
		//only delete non-admins
		if(!user_can($user_id, "manage_options"))
		{
			//remove the delete hooks so we don't try to cancel the membership again
			remove_action('delete_user', 'pmpro_delete_user');
			remove_action('wpmu_delete_user', 'pmpro_delete_user');
			
			//delete the user
			require_once(ABSPATH . "/wp-admin/includes/user.php");
			wp_delete_user($user_id);	
			
			//add the delete hooks back in
			add_action('delete_user', 'pmpro_delete_user');
			add_action('wpmu_delete_user', 'pmpro_delete_user');
		}
	}
}
add_action("pmpro_after_change_membership_level", "my_pmpro_after_change_membership_level", 10, 2);

Used this and still works perfectly. Thanks!
In answer to previous commenter, you place in functions.php in theme editor.

This recipe is included in the blog post on "Delete the WordPress user when a PMPro member cancels" at Paid Memberships Pro here: https://www.paidmembershipspro.com/delete-the-wordpress-user-when-a-paid-memberships-pro-member-cancels-his-account/